Automatic drain valve



Filed April 24, 1947 INVENTOR Burton SAilmmn QM awa A ATTORNEY PatentedMay 16, 1950 AUTOMATIC DRAINVALVE" Burton S. Aikman, Wilkinsburg Pa.,assignor to The Westinghouse Air Brake Company, Wilmet-ding, Pa., acorporation of Pennsylvania- Application April 24, 1947, Serial No.743,533

This invention relates to automatic drain. valve devices and moreparticularly to the type employed with the reservoir or receiverof afluid pressure system to drain moisture which accumulates in thereservoir or receiver.

In the operation of fiuid pressure systems, air from the atmosphere iscompressed and is stored in a reservoir or receiver from which fluid iswithdrawn as required.

Fluid under pressure supplied to a reservoir or receiver by a fluidcompressor is usually cooled while being stored therein, with theresultthat a substantial amount of its vapor content condenses in thereservoir. If this condensate is allowed to accumulate in the reservoir,it not only reduces the fluid pressure volume of said reservoir, but mayfind its way into a system utilizing fluid under pressure therefrom andcause operational failure or damage to the equipment com prised in saidsystem.

It is an object of this invention to provide a drain valve deviceadapted to be employed with the reservoir of a fiuid'pressure system toautomatically prevent accumulation of condensate in chamber to actuate avalve device to drain the condensate from said chamber.

Another object of the invention is to provide an improved drain valvedevice of the type hereinbefore mentioned which may be easily attached Lto a reservoir of the type employed in fluid pressure systems.

Other objects and advantages of the invention will become apparent fromthe-followingmore detailed description taken in connection with theaccompanying drawing, the single figure of which is a. sectional view ofa portion eta reservoir equipped with the drain valve device embodyingthe invention.

Description Referring to'the' drawing, there is illustrated a-portion ofa reservoir l for a fluid pressure sys tem which is adapted to besupplied with fluid under pressure by a suitable compressor (not shown)and from which fluid may-flow by way of a suit- 5 Claims. (Cl. 13'768)able pipe (not shown) for use'in controlling fluid pressure devices orthe like.

The reference numeral 2 designates a drain valve device, embodying theinvention, and comprises a hollow body portion 2a, a magnet valve device3 and a fixed mounting'base or bracket 4 upon which are mounted the bodyportion 2a and the magnet valve device 3. This drain valve device 2 islocated below the reservoir I and the interior of the reservoir is inconstant open communication with a condensate collecting chamber 5 inthe body portion 2a by way of a drain pipe 6 which preferably hasscrew-threaded connections with both the reservoir and top of the bodyportion 2a-whereby bygravity condensate may drain from the reservoirinto said chamber.

Disposedwithin the hollow body portion 2a is a float 1 loosely mountedon a guide rod 8 to provide a clearance space 30 therebetween. The

' rod 8 is secured tothe mounting base 4 at 29 andis encircled by anannular space or cavity 2'! formed in saidbase, which cavity is open toa passage 23. Encircling cavity 2! is a seat 29 for the float LMountedon the upper face of the float! is an electrical contact in theform of a metallic contact ring "9 adapted to engage a pair of spacedcontact fingers In which are mounted in suitable insulating members llsecured in the body portion 2a adjacent the drain pipe 5.

One of the contact fingers iii is connected to a circuit wire Illeadlngfrom one of the terminals of a battery l3. The other contact finger fl!is connected to-a wire i241 leading to the magnet valvedevice 3.

The magnet valve device '3 may comprise a casing I 4 havinga chamber l5arranged at one side of a flexible diaphragm I! which is clamped betweensaid casing and the mounting base 4. At the opposite side of diaphragmI! is a chamber 15 in the base 4. The magnet valve device also comprisesa-coil or winding H! which has one end connected to the wire l2a leadingfrom one of the contact fingers"). The'ot-her end of the coil l 3 isconnected "to a wire ls'which is connected to the other terminal of thebattery l3. The magnet valve devicefurther 'comprises'an armature 29connected to the center of diaphragm l1 and having formed on one end avalve 22 disposed in chamber I6 for cooperation with a seat on themounting base 4 for controlling communication between chamber lfi and apassage '23 leading to float chamber 5. Uponenergization of coil .8 thearmature ibis adapted to unseat the valve 22. A spring '2! acting-onzthearmature is provided to seat valve 22.. upon deenergization. of 1 coilI8.

Chamber I 8 is open to atmosphere through a choke 24 and passage 25.

Operation Assuming that winding I8 of the magnet valve device 3 isdeenergized and the several parts of the drain valve device are in theposition in which they are shown in the drawing, and that fluid underpressure is being supplied to the reservoir I and thence through pipe 6to the chamber 5. From the chamber 5 fluid under pressure will flowthrough the clearance space 30 between the guide rod 8 and the float "Ito the space 21 between the undersuriace of the float and the adjacentsurface of the base portion 4 so as to partially counterbalance thepressure of fluid acting over the upper surface of the float. Fluidunder pressure from space 21 will flow through passage 23 to the seatedmagnet valve 22.

Condensate as it collects in the reservoir I drains through pipe 6 intochamber 5. Now when the condensate in chamber 5 reaches a certain levelit will lift the float from contact with the base 4 and open chamber 5directly to cavity 2'! and passage 23. When the accumulated condensatein chamber 5 is suflicient to cause the float I to move the ring 9 intoengagement with both contact fingers ID, the electric circuit throughthe winding I8 of the magnet valve device and battery I3 is closed thusenergizing the winding I 8. With the winding I8 energized the armature20 is caused to move upwardly against the o pposing pressure of thespring 2I, flexing the diaphragm I! upwardly and unseating the valve 22.

With the valve 22 unseated the accumulated condensate in the passage 23and chamber 5, which is under the pressure of fluid from the reservoirI, will flow to chamber IE and thence to atmosphere through choke 24 andexhaust port 25. As the condensate from chamber 5 is discharged toatmosphere, the level of condensate in said chamber will fall and alongwith it the float 1 and ring 9 until said ring moves out of engagementwith the contact fingers I and opens the circuit through the winding I8of the magnet valve device and battery I3 thus deenergizing the coil.However, the valve 22 will remain open upon deenergization of the magnetuntil the float I engages the base 4, since the choke 24 so restrictsdischarge of condensate from chamber It as to maintain sufficientpressure on the lower face of flexible diaphragm I1, as to hold saiddiaphragm deflected against spring 2| and thus hold valve 22 unseatedagainst the opposing pressure of said spring until substantially all ofthe condensate has been discharged from chamber and float I has returnedto its lower most position in chamber I3 contacting seat 28. With thefloat I in contact with seat 28, the flow of condensate from chamber 5to passage 23 is restricted by the clearance space 30 to a rate lessthan the rate at which fluid flows from chamber IE to atmosphere by wayof the choke 24 and exhaust port 25 and, as a result, the pressure offluid in chamber I6 will promptly reduce and permit the spring 2I tomove the armature downward to seat the valve 22, the diaphragm I!returning to its normal position with the armature.

Summary From the above description it will now be seen that the improveddrain valve device will operate each time chamber 5 becomes suflicientlyfilled with condensate to cause energization of magnet valve device 3 todischarge such condensate and 4 thereby prevent condensate fromaccumulating in the reservoir I.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. An automatic drain valve device for discharging condensate from afluid pressure system, comprising a casing having a condensatecollecting chamber in constant open communication with said fluidpressure system, a condensate drainage communication leading from saidchamber, electromagnetic valve means normally closing said condensatedrainage communication and operative upon energization to open said communication, switch means comprising a guide rod in said chamber, a floatslidably mounted on said guide rod, an electrical contact carried bysaid float, and a pair of contact fingers carried by said casing andadapted to be engaged by said electrical contact in response to apredetermined increase in the amount of condensate collected in saidchamber for efiecting energization of said valve means and beingresponsive to the partial discharge of collected condensate from saidchamber to move said electrical contact out of engagement with saidfingers to effect deenergization of said valve means, control meansresponsive to the pressure of condensate discharged from said chamberfor maintaining said valve means in its condensate drainagecommunication opening position, said float being responsive tosubstantially complete discharge of condensate from said chamber forrestricting flow of fluid under pressure from said chamber to saiddrainage communication to a rate less than the rate of flow ofcondensate from said drainage communication to effect a reduction in thepressure of condensate on said control means, and means operative uponsaid reduction in the pressure of the condensate acting on said controlmeans for actuating said valve means to close said drainagecommunication.

2. An automatic drain valve device for discharging condensate from afluid pressure system, comprising a casing having a condensatecollecting chamber in constant open communication with said fluidpressure system, a condensate drainage communication leading from saidchamber, an electrically controlled valve device comprising a flexiblediaphragm, a valve operatively associated with said diaphragm normallyclosing said condensate drainage communication and operative to open thecommunication, a magnet operative upon energization to actuate saidvalve to open said communication, a spring for actuating said valve toclose said communication, a source of electrical energy, switch meansoperative to connect said source of electrical energy into circuit withsaid magnet to effect the energization of said magnet winding andoperative to open said circuit to effect deenergization of said magnet,said switch means compris ing a guide rod disposed in said chamber, afloat slidably mounted on said guide rod, an electrical contact carriedby said float, and a pair of contact fingers carried by said casing andadapted to be engaged by said electrical contact ring in response to apredetermined increase in the amount of condensate collected in saidchamber for closing said circuit, and being responsive to the partialdischarge of collected condensate from said chamber to move saidelectrical contact out of engagement with said contact fingers to opensaid circuit, said flexible diaphragm being responsive to pressure ofcondensate being discharged from said chamber for maintaining said valveopening said condensate drainage communication against the opposingpressure of said spring upon deenergization of said magnet, and saidfloat being responsive to substantially complete discharge of condensatefrom said chamber for restricting the flow of fluid under pressure fromsaid chamber to said drainage communication to a rate less than the rateof flow of condensate from said drainage communication to thereby eflecta reduction in the pressure oicondensate acting on said flexiblediaphragm for rendering said spring effective.

3. An automatic drain valve device for discharging condensate from afluid pressure system, said device comprising a casing having acondensate collecting chamber in constant open communication with saidfluid pressure system, a condensate drainage communication leading fromsaid chamber, electromagnetic valve means normally closing saidcondensate drainage communication and operative upon energization toopen said communication, a source of electrical energy, a normally openelectric circuit associated with said electromagnetic valve means andsaid source of electrical energy, a float movably mounted in saidcondensate collecting chamber, an electric switch member operative toopen and close said circuit, said float being movable in response to acertain increase in the amount of condensate in said condensatecollecting chamber to cause said switch member to close said electriccircuit through said electromagnet valve device and said source ofelectrical energy to thereby efiect the energization of theelectromagnetic valve means, means responsive to the pressure ofcondensate discharged from said chamber for actuating said valve meansto maintain said condensate discharge communication open, said floatbeing responsive to the substantially complete discharge of condensatefrom said chamber for restricting the flow of fluid under pressure fromsaid chamber to said drainage communication to a rate less than the rateof flow of condensate from said drainage communication to efiect areduction in the pressure of the condensate acting on said valve means,and means responsive to the reduction in pressure of condensate on saidvalve means for actuating said valve means to close said drainagecommunication.

4. An automatic drain valve device for discharging condensate irom afluid pressure system, said device comprising a casing having acondensate collecting chamber in constant open communication with saidfluid pressure system, a condensate drainage communication leading fromsaid chamber, an electrically operated valve device comprising aflexible diaphragm, a valve operatively associated with one side of saiddiaphragm and normally closing said condensate drainage communication, amagnet operative upon energization to efiect operation of said valve toopen said communication, a source of electrical energy, a normally openelectrical circuit associated with said source of electrical energy andsaid electrically operated valve device, switch means operative to openand close said circuit, and a float responsive to a certain increase inthe amount of condensate collected in said chamber for effecting theoperation of said switch means to close said circuit to thereby effectthe energization of said magnet and responsive to a partial discharge ofcollected condensate from said chamber to effect the operation of saidswitch means to open said circuit to thereby effect the deenergizationof said magnet, said flexible diaphragm being responsive to the pressureof the condensate being discharged from said chamber for maintainingsaid valve open, said float being responsive to substantially completedischarge of condensate from said chamber for restricting flow of fluidunder pressure from said chamber to said drainage communication to arate less than the flow of condensate from said drainage communicationto effect a reduction in the pressure of condensate acting on saiddiaghragm, and spring means acting on said diaphragm for actuating saidvalve to close said drainage communication upon eflecting said reductionin the pressure of the condensate on said diaphragm.

5. An automatic drain valve device for discharging condensate from afluid pressure system, said valve device comprising a casing having acondensate collecting chamber in open communication with said system,valve means controlling a condensate discharge communication from saidchamber, an electromagnet operable upon energization to efiect operationof said valve means to open said communication, a source of electricalenergy, a normally open electrical circuit associated with said sourceof electrical energy and said electromagnet, switch means operative toopen and close said circuit, and a float responsive to a certain amountof condensate in said chamber to effect the operation of said switchmeans to close said circuit to thereby effect the energization of saidmagnet and responsive to a reduction in the amount of condensate in saidchamber to efiect the operation of said switch means to open saidcircuit to thereby efiect the deenergization of said magnet, said floatbeing operative upon the substantially complete discharge of condensatefrom said chamber to restrict such discharge, control means formaintaining said valve means in its communication opening position upondeenergization of said magnet, said control means being renderedineifective upon the restricting of the discharge of condensate fromsaid chamber by said float, and means for actuating said valve means toclose said communication upon rendering said control means ineffective.

BURTON S. AIKMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,529,334 Winkeleer Mar. 10, 19251,747,498 Archibald Feb. 18, 1930

